<nav class="nav">
  <a class="button" routerLink="/">Home</a> |
  <a class="button" routerLink="/material">material</a> |
  <a class="button" routerLink="/page3">page3</a>
</nav>
<router-outlet></router-outlet>
<style>
  .nav {
    padding-bottom: 10px;
  }
</style>
